One useful attribute of block copolymers is their ability to combine the disparate properties of different materials into a single material. For example, a polymer of styrene-butadiene-styrene, a thermoplastic elastomer, draws its elastomeric qualities from the low glass transition, viscoelastic butadiene segments, and its dimensional stability and melting behavior from the high glass transition, rigid styrene segments. This combination of properties is achieved by arranging the constituent monomers in a particular sequential architecture, i.e., a so-called block copolymer.
An additional feature of block copolymers is their ability to localize at the interface of two materials thereby modifying the chemical and physical bond between the two. In order to localize in this manner, the block copolymer must be comprised of segments which have a specific chemical or physical affinity for the respective materials. This feature has been employed for the compatibilizing blends and improving adhesion.
The ability of certain polymer segments of block copolymers to localize at the air/material interface to thereby modify the surface has also been noted. In each instance, such a surface modification employs low surface energy polymer segments that are not highly branched to provide the physical driving force to enrich the surface with these polymer segments.